Are we seeing a trend here? I don't even know if Betty Ross had a job in the old Hulk stories; wasn't she more or less a housekeeper for her father? I left Aquaman out of the mix because for some odd reason his Silver Age adventures did not start with a romantic interest; it was not until Aquaman #11 that Mera appeared on the scene. And you can make a case for talking about Sue Storm being a scientist, although it might help if Stan and Jack had shown her mixing up some chemicals in her spare time instead of trying on new clothes and hairstyles.

All the Marvel heroines performed one valuable function; they made excellent hostages. Let's consider Jane Foster, for example:

Now it is not entirely fair to criticize this as sexist; it's also provides strong motivation for the hero. Hostages help balance out the power differences between superheroes and the (often non-super) villains. And it's not as if only women were used in this way; Jimmy Olsen and Robin often found themselves kidnapped as well.